There have conventionally been known electronic component mounting apparatuses for mounting electronic components to objects while transferring, with use of arms, the objects to which the electronic components are to be mounted. There is, for example, an electronic component mounting apparatus of a type which mounts TCPs (Tape Carrier Package) onto liquid crystal panels.
FIG. 19 is a perspective view of a conventional electronic component mounting apparatus of one example in its entirety. Electronic component mounting apparatus 51 shown in this figure is an apparatus for mounting TCPs onto liquid crystal panels, which includes an ACF attachment part 52, a TCP temporary pressure bonding part 53, and a TCP permanent pressure bonding part 54. Transfer arms 55 are set so as to transfer liquid crystal panels. A liquid crystal panel handed to a transfer arm from outside the apparatus is sequentially sent to an adjacent transfer arm after completely being processed at each of the parts 52–54, so that the liquid crystal panel is transferred in a direction of arrow “a”.
A perspective view of FIG. 20 concretely illustrates how each transfer arm holds a liquid crystal panel. A suction pad (not shown) is formed on a disc part 55a of transfer arm 55. Liquid crystal panel 60 is held by the transfer arm 55 from above, i.e., from a side of a display face, through vacuum suction by the suction pad.
The liquid crystal panel 60 held in this state can be transferred in the direction of the arrow “a” (FIG. 19), in other words, can be transferred to an adjacent subsequent process. Concretely, the liquid crystal panel 60 completely finished at each part such as the ACF attachment part 52 or the like is transferred in a direction of arrow “b” by a panel stage 56 set below the liquid crystal panel 60, and is brought into a state of FIG. 20.
In this state, the liquid crystal panel 60 is delivered to the transfer arm 55 which in turn holds the liquid crystal panel 60 from above. The liquid crystal panel is then transferred in the arrow “a” direction. The liquid crystal panel 60 having an ACF attached thereto by the ACF attachment part 52 is transferred to a position opposite to the TCP temporary pressure bonding part 53, which is the next process.
However, the conventional electronic component mounting apparatus as above has problems as follows. Liquid crystal panels have been increasingly made large and thin these days; thus making it necessary to increase a hold force of the transfer arm 55, namely, a vacuum suction force of a corresponding suction pad. This increase of the hold force brings about an irregularity (shaded parts c) in suction by the suction pad at a periphery of the suction pad, and this suction irregularity leads to a display irregularity in highly fine and high-quality liquid crystal panels, thereby lowering an image quality.
Liquid crystal panels must be removed from the apparatus in case of maintenance. However, the transfer arms 55 above the liquid crystal panels make it impossible to remove the liquid crystal panels even when the conventional electronic component mounting apparatus as above comes to a halt because of a failure or the like, or require complicated work even if it is possible.
The present invention is devised to solve the problems inherent in this prior art, and has for its first object to provide an electronic component mounting apparatus which can prevent damage to objects, to which electronic components are to be mounted, by holding the objects from below when transferring the objects, with a maintainability improved.
The above-described conventional component mounting apparatus still includes problems as below. That is, there is a liquid crystal panel 71, for instance, having a liquid crystal display part 74 set to a surface of a glass plate 73 as shown in FIG. 22. An electronic component 72 for operating the liquid crystal display part 74 is mounted at a periphery of the liquid crystal display part 74, more specifically, to a side edge part 73a of the glass plate 73. For mounting the electronic component 72 to a component mount position of the side edge part 73a, as indicated in FIG. 23, an image of a panel mark on the side edge part 73a is picked up and recognized by a camera 75, while an image of a component mark on the electronic component 72 is picked up and recognized by, e.g., the same camera 75. On a basis of these recognition results of the panel mark and component mark, a location of the liquid crystal panel 71 is corrected with a panel hold device 76 which holds the liquid crystal panel 71 and corresponds to a panel stage, which correction is achieved by moving the panel 71 in X and Y directions and moreover rotating the panel 71 about an axis of a shaft 77 of the panel hold device 76. At the same time, the electronic component 72 is rotated about an axis of a component hold member 78 holding the electronic component 72, thereby resulting in the component being corrected in terms of position. The electronic component 72 is mounted to a specific component mount position in this manner.
As shown in FIG. 23, conventionally, the liquid crystal panel 71 is held at its nearly central part by a hold part 79 of the panel hold device 76. Since the panel hold device 76 is movable in the X and Y directions as mentioned above, the hold part 79 is limited in size in order to avoid interference with other devices.
Under these circumstances, while liquid crystal panels of a several-cm square used in, for example, mobile phones or the like are accompanied with no problem, in the liquid crystal panel 71 having the glass plate 73 of a large size not smaller than 10 inches, e.g., 15 inches or 21 inches, a large amount of deflection at a component mount position has arisen when this large size panel 71 is held by the hold part 79 as shown in FIG. 24. Therefore, an error corresponding to this deflection amount is generated between when an image of the liquid crystal panel 71 is picked up by the camera 75 and when the electronic component 72 is mounted to the liquid crystal panel 71. Accordingly, in the liquid crystal panel 71 of such a large size, the deflection amount consequently affects positional correction of the liquid crystal panel 71 as above, thereby making it difficult to mount the electronic component 72 to a specified component mount position.
In addition, since latest liquid crystal panels 71 have been made thinner and lighter in weight, a deflection amount of liquid crystal panels 71 is apt to increase as well as in consequence of the above size increase, as shown in FIG. 25. A deflection amount is hence considered to further hinder the electronic component 72 from being mounted to a specified component mount position. The deflection amount indicated in FIG. 25 is a dimension between an uppermost end and a lowest end of a deflected liquid crystal panel.